From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Eric S. Johansson" Subject: trouble with mega-raid 150 and considering other alternatives Date: Wed, 09 Jan 2008 15:04:45 -0500 Message-ID: <478528DD.7080802@harvee.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids (originally posted through gmane but after few hours I haven't seen it come through hence the potential repost) Ububtu 6.06 LSI Megaraid 150-4 what I am looking for is a bit of education about how to diagnose raid five performance problems and whether or not I'm barking up the wrong tree with the megaraid 150 card I'm using. as you can see by the bonnie runs, I have a significant difference in performance between a raid five array and a standalone disc. I expect some performance difference but, this is a bit much. I've tried to look at options for configuring the array but unfortunately, LSI doesn't make it easy. I'm considering saying "to hell with hardware raid" and heading back to software raid. at the same time, I would like to try and understand what's causing the failure because it appears that I'm having a similar failure with another raid system. The performance problem was detected because I was running virtual machines on the server and every time the application ran, on the host, wait state would climb significantly, sometimes as high as the mid-90s. Load average would climb around 5-6. On the other machine which is causing me fits (promise raid array on the other end of the SCSI bus from an Adaptec 160 SCSI controller, has wait state frequently in the mid-80s to mid 90s and load averages around 15 to 20. I figure if I learn enough to solve the problem on my system, I can solve it on the other. thanks ---eric root@vesta:/var/backup# bonnie -d /var/backup/bonnie -u esj Version 1.03 ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP vesta 2528M 6945 24 7739 2 3771 1 6633 23 9427 2 118.7 1 ------Sequential Create------ --------Random Create-------- -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 526 9 +++++ +++ 546 5 515 6 +++++ +++ 573 5 vesta,2528M,6945,24,7739,2,3771,1,6633,23,9427,2,118.7,1,16,526,9,+++++,+++,546,5,515,6,+++++,+++,573,5 on single disk: root@vesta:/var/backup# bonnie -d /tmp -u esj Version 1.03 ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP vesta 2528M 16524 65 53783 24 20995 8 19121 67 54373 13 128.8 1 ------Sequential Create------ --------Random Create-------- -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 1112 76 +++++ +++ +++++ +++ 1296 86 +++++ +++ 2666 83 vesta,2528M,16524,65,53783,24,20995,8,19121,67,54373,13,128.8,1,16,1112,76,+++++,+++,+++++,+++,1296,86,+++++,+++,2666,83